1. Field of the Invention
The present invention relates to test equipment and more particularly to equipment for probing, testing, burn-in, repairing, programming and binning of integrated circuits.
2. Description of the Related Art
In conventional semiconductor equipment technologies, separate pieces of equipment are required to test, burn-in, repair, program and bin integrated circuits (ICs). Integrated circuits that are in wafer form are tested or screened for packaging using a tungsten needle probe card, wafer positioning equipment called a prober and automatic test equipment (ATE) which supplies test signals to the probe card and determines the validity of any output signals. A probe card is a connector that provides a mechanical means for making a temporary contact to the contact pads on an IC for the purpose of testing the IC. The probe card may contact only a single die, but it may typically contact as many as eight or more dice if the dice consist of memory ICs. A die typically consists of one IC; however, it may include a plurality of ICs. Conventional probe cards do not provide the capability of contacting all the dice on a wafer at once.
An IC is typically burned-in and speed-graded prior to its use or sale. Burn-in of circuit devices requires many hours of testing the devices under stressing temperature and electrical conditions. An IC is burned-in to lower the possibility that it will fail after it is inserted into an electronic assembly such as a Multi-Chip Module (MCM) or printed circuit board (PCB) of other ICs. Burn-in of an IC is performed typically after the IC is in packaged form. Burn-in fixtures for processing a die before packaging, so called bare die burn-in, are beginning to become available. Whether an IC is in packaged form or in die form, a separate piece of equipment is used to burn-in an IC. After an IC has been burned-in, it is speed-graded or binned using automatic test equipment. Binning is a process that sorts ICs according to their performance characteristics.
When an IC is in wafer form, and it contains shorts that disrupt the functionality of the IC, it may be repaired by removing portions of a deposited layer (e.g., a polysilicon layer or an aluminum metal layer). A laser cutting machine is typically used to perform the circuit repair. If an IC is a memory circuit array, yet another machine is required to program the memory circuit array by fusing or anti-fusing circuits within the memory circuit array. Subsequent to repair of an IC, the IC must be tested again.
It would be advantageous, and is therefore an object of the present invention to provide a single piece of equipment that can perform all of the functions mentioned above that are previously done by separate pieces of equipment to reduce capital equipment expense and the number of steps required for IC burn-in, testing, repairing and/or programming.